Brand:
Toyota
Model Name:
4Runner GRN210 215 UZN210 215
Manual:
Repair Manual
Section:
2Uz-Fe Engine Control System
Title:
Sfi System
DTC P0455 Evaporative Emission Control System Leak Detected (Gross Leak)
DTC P0456 Evaporative Emission Control System Leak Detected (Very Small Leak)
DTC SUMMARY
| DTC No. | Monitoring Items | Malfunction Detection Conditions | Trouble Area | Detection Timing | Detection Logic |
| P0455 | EVAP gross leak | Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure measured. 0.02 inch leak criterion measured at start and at end of leak check. If stabilized pressure higher than [second 0.02 inch leak criterion x 0.2], ECM determines that EVAP system has large leakage. |
| While ignition switch OFF | 2 trip |
| P0456 | EVAP small leak | Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure measured. 0.02 inch leak criterion measured at start and at end of leak check. If stabilized pressure higher than second 0.02 inch leak criterion, ECM determines that EVAP system has small leakage. | Same as above | While ignition switch OFF | 2 trip |
DESCRIPTION
The circuit description can be found in the Evaporative Emission (EVAP) system (Click here).INSPECTION PROCEDURE
Refer to the EVAP system (Click here).MONITOR DESCRIPTION
5 hours* after the ignition switch is turned OFF, the leak detection pump creates negative pressure (vacuum) in the EVAP system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.- HINT:
- *: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned OFF, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned OFF, the monitor check starts 2.5 hours later.
| Sequence | Operations | Descriptions | Duration |
| - | ECM activation | Activated by soak timer 5, 7 or 9.5 hours after ignition switch OFF. | - |
| A | Atmospheric pressure measurement | Vent valve turned OFF (vent) and EVAP system pressure measured by ECM in order to register atmospheric pressure. If pressure in EVAP system not between 70 kPa and 110 kPa (525 mmHg and 825 mmHg), ECM cancels EVAP system monitor. | 10 seconds |
| B | First 0.02 inch leak criterion (reference pressure) measurement | In order to determine 0.02 inch leak criterion, leak detection pump creates negative pressure (vacuum) through reference orifice and then ECM checks if leak detection pump and vent valve operate normally. | 60 seconds |
| C | EVAP system pressure measurement | Vent valve turned ON (closed) to shut EVAP system. Negative pressure (vacuum) created in EVAP system, and EVAP system pressure then measured. Write down measured value as it will be used in leak check. If EVAP pressure does not stabilize within 900 seconds, ECM cancels EVAP system monitor. | 900 seconds* |
| D | Purge VSV monitor | Purge VSV opened and then EVAP system pressure measured by ECM. Large increase indicates normal. | 10 seconds |
| E | Second 0.02 inch leak criterion (reference pressure) measurement | After second 0.02 inch leak criterion measurement, leak check performed by comparing first and second 0.02 inch leak criterion. If stabilized system pressure higher than second 0.02 inch leak criterion, ECM determines that EVAP system leaking. | 60 seconds |
| F | Final check | Atmospheric pressure measured and then monitoring result recorded by ECM. | - |
![P0455: EVAP gross leakIn operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than [second 0.02 inch leak criterion x 0.2] (near atmospheric pressure), the ECM determines that the EVAP system has a large leakage, illuminates the MIL and sets the DTC (2 trip detection logic). 4Runner](/sites/default/files/4runner_grn210_215_uzn210_215/a112612e02.png)
- P0455: EVAP gross leak
In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than [second 0.02 inch leak criterion x 0.2] (near atmospheric pressure), the ECM determines that the EVAP system has a large leakage, illuminates the MIL and sets the DTC (2 trip detection logic). - P0456: EVAP very small leak
In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than the second 0.02 inch leak criterion, the ECM determines that the EVAP system has a small leakage, illuminates the MIL and sets the DTC (2 trip detection logic).
MONITOR STRATEGY
| Related DTCs | P0455: Gross leak detected P0456: Very small leak (0.020 inch hole) detected |
| Required sensors/Components | Purge VSV, Pump module |
| Frequency of operation | Once per driving cycle |
| Duration | Within 15 min. (varies with amount of fuel in tank) |
| MIL operation | 2 driving cycles |
| Sequence operation | None |
TYPICAL ENABLING CONDITIONS
| The monitor will run whenever these DTCs are not present | None |
| Atmospheric pressure | 70 to 110 kPa (525 to 825 mmHg) |
| Battery voltage | 10.5 V or more |
| Vehicle speed | Less than 2.5 mph (4 km/h) |
| Ignition switch | OFF |
| Time after key off | 5 or 7 or 9.5 hours |
| EVAP pressure malfunction (P0450, P0452, P0453) | Not detected |
| EVAP canister purge valve | Not operated by scan tool |
| EVAP canister vent valve | Not operated by scan tool |
| EVAP leak detection pump | Not operated by scan tool |
| Both of the following conditions are met before key off | Condition 1 and 2 |
| 1. Duration that vehicle has been driven | 5 minutes or more |
| 2. EVAP purge operation | Performed |
| ECT | 4.4 to 35°C (40 to 95°F) |
| IAT | 4.4 to 35°C (40 to 95°F) |
Key-off monitor sequence 1 to 8
| Next sequence is run if the following condition is met | - |
| Atmospheric pressure change | Within 0.3 kPa (2.25 mmHg) in 1 second |
| Next sequence is run if the following conditions set | - |
| EVAP pressure just after reference pressure measurement start | -1 kPa (-7.5 mmHg) or lower |
| Reference pressure | -4.85 to -1.05 kPa (-36.38 to -7.93 mmHg) |
| Reference pressure | Saturated within 60 seconds |
| Next sequence is run if the following conditions set | - |
| EVAP pressure change after vent valve is ON | 0.3 kPa (2.25 mmHg) or more |
| Next sequence is run if the following conditions set | - |
| EVAP pressure | Saturated within 900 seconds |
| Next sequence is run if the following conditions set | - |
| EVAP pressure change after purge valve is open | 0.3 kPa (2.25 mmHg) or more |
| Next sequence is run if the following conditions set | - |
| EVAP pressure just after reference pressure measurement | -1 kPa (-7.5 mmHg) or lower |
| Reference pressure | -4.85 to -1.05 kPa (-36.38 to -7.93 mmHg) |
| Reference pressure | Saturated |
| Difference between first reference pressure and second reference pressure | Less than 0.7 kPa (5.25 mmHg) |
| Next sequence is run if the following conditions set | - |
| EVAP pressure when vacuum introduction is complete | Lower than second reference pressure |
| EVAP monitor is complete if the following conditions set | - |
| Atmospheric pressure difference between sequence 1 and 8 | Within 0.3 kPa (2.25 mmHg) |
TYPICAL MALFUNCTION THRESHOLDS
| EVAP pressure when vacuum introduction is complete | Between reference pressure and reference pressure x 0.2 |
| EVAP pressure when vacuum introduction is complete | Higher than reference pressure x 0.2 |